[Insight-users] Orthogonality tolerance test

[Andriy Fedorov]

Hi,

What is the motivation for setting the tolerance in matrix orthogonality
test to 1e-10 in itkRigid3DTransform.cxx?

I have a transform produced by FSL FLIRT tool, which is orthogonal with
tolerance 1e-5. I am trying to re-shape this transform to an ITK
transform (FSL uses different origin conventions), so that I can import
it into Slicer. With the current tolerance setting this is not possible,
the code breaks when I am trying to set the matrix.

Is the current check with 1e-10 tolerance level a correct and necessary
precaution? Isn't it too strict for practical purposes?

Thanks

Andriy Fedorov